Handbook of air conditioning and refrigeration / Shan K

The leakage area to the elevator shaft is
A leak � 3 � 0.25 � 1000 � 0.00084 � 1.59 ft 2
If the total opening at the top of the elevator shaft is 5 ft 2 , assume that only 0.5 ft 2 will be allocated
for the open stairwell door. For an airflow path a-b-o, if the pressure drop at the open door is negligible,
the effective area is
For airflow path a-c-d-o, the effective area is
A e �� 1
A 1 2
For airflow path a-c-e-f-o, the effective area is
For airflow path a-k-l-o, the effective area is
AIR SYSTEMS: FAN COMBINATION AND SMOKE CONTROL 22.37
FIGURE 22.9 Air discharged from an open stairwell door through a
combined air path to the outdoors.
�� 1 1 1
� � 2 2 0.52 0.52 1
A e �� 1
1.59
Ae �� 1 �1 / 2
A2� � 1 ft
1 2
�1 / 2 1
�
A2� 2
A e �� 1
A 1 2
�� 1
0.52
� 1
A 2 2
1
� 2 0.5
1
� 2 1
�1 / 2 1
�
A2� 3
2��1 / 2
2��1 / 2
2��1 / 2
� 0.48 ft 2
� 0.46 ft 2
� 0.35 ft 2
The effective area of airflow path a-g-h-o is the same as that of a-c-d-o, that is, 0.46 ft 2 ; and the
effective area for a-g-i-j-o is the same as that of a-c-e-f-o, that is, 0.35 ft 2 . Therefore, the total